1. Adding & Subtracting Large Numbers Adding & subtracting by focusing on the place value of the digits 3.4

2. Guiding Questions How can understanding place value help you solve addition and subtraction problems with larger numbers?

3. Warm Up: Closest Estimate 42 x 18 What’s the closest estimate? 420 800 840 Would the estimate we chose be greater than or less than the actual answer? How do you know that? Turn & talk, figure it out without finding the actual answer

4. Adding & Subtracting Large Numbers Today we will work with numbers larger than 10,000. We will start by solving related problems. As I show each one, think about how the answer to the previous problem can help you solve the new problem. You should be able to do these mentally. 12,385 – 200 = 12,385 – 210 = 12,385 – 212 =

5. Story Context There are 12,385 people at a basketball game. If 200 of them leave the game, we know that 12,185 people are left. Use this story to tell me what 12,385 – 210 means. Will the answer to this problem be more or less than 12,195? How do you know? What about 12,385 – 212? How does that work with this story? Would the answer be more, or less, than 12,385 – 210?

6. More sets of problems 7,653 + 400 = Compare 7,653 and the sum. Which digits are the same? Different? Why? 7,653 + 420 = Compare the sum of the first problem with the sum of this one. 7,663 + 420 = How can the previous sum help you solve this problem?

7. VERY large numbers 1,000 one thousand 10,000 ten thousand 100,000 one hundred thousand 1,000,000 one million 10,000,000 ten million 100,000,000 one hundred million 1,000,000,000 one billion

8. Place Value Chart Billions Millions Thousands UnitsDecimals

9. Fun With Numbers Write down a really, really big number, something with more than 5 digits. Add 10 to it and show how the new number is different. Add or subtract a few different numbers that are multiples of 10, 100, 1,000 to your really big number and work with a partner to see how your number changes!

10. Guiding Questions How can understanding place value help you solve addition and subtraction problems with larger numbers?